Miso Soup is a traditional Japanesesoup consisting of a stock called "dashi" into which softened miso paste is mixed. Many ingredients are added depending on regional and seasonal recipes, and personal preference.

The choice of miso paste for the miso soup defines a great deal of its character and flavor. Miso pastes (a traditional Japanese seasoning produced by fermenting soybeans with salt and the fungus Aspergillus oryzae, known in Japanese as kōjikin (麹菌?), and sometimes rice, barley, or other ingredients) can be categorized into red (akamiso), white (shiromiso), or mixed (awase). There are many variations within these themes, including regional variations, such as Shinshū miso or Sendai miso.A miso paste that has been fermented for a longer period of time, such as a red miso, gives the miso soup a stronger, deeper flavor. A miso paste that has been fermented for a shorter period of time, such as a white miso, provides a lighter, sweeter flavor.More than 80% of Japan's total annual production of miso goes into miso soup, and 75% of all Japanese consume miso soup at least once a day.